By Steve Holland

CLEVELAND (Reuters) - As Republicans spilled into Cleveland on Monday to nominate Donald Trump as their presidential candidate, 2012 nominee Mitt Romney had an equally crucial task: Entertaining his grandchildren at his lakeside summer house in New Hampshire.

U.S. Senator John McCain of Arizona, the 2008 Republican nominee who has endorsed Trump despite the latter's insults, attended an ice cream party with his wife, Cindy, and volunteers in his re-election campaign in Prescott, Arizona. He also took part in a veterans' gathering.

"Working out of my office in Miami this week," former Florida Governor Jeb Bush, who dropped out of the Republican presidential race in February, said in an email to Reuters. Bush had been the most active in attacking Trump on the campaign trail and has said he will not be voting for either Trump or Democrat Hillary Clinton on Nov. 8.

His brother, former President George W. Bush and father, former President George H.W. Bush, were also not at the Republican National Convention in Cleveland.

These are some of the big names from a long list of prominent Republicans who are not venturing this week to Cleveland, where Trump is to be formally nominated on Thursday after a rough-and-tumble Republican primary fight that ripped wounds in the party that have yet to heal.

Trump campaign manager Paul Manafort told reporters the convention is a "healing time" for the party and that Republicans will leave Cleveland united, but he criticized Ohio Governor John Kasich for not participating in an event in his own backyard.

And Republicans have moved past the Bush era, he added.

“They’re part of the past. We’re dealing with the future," he said.

Kasich, a one-time rival of Trump's for the nomination, is making the rounds in Cleveland without endorsing Trump or speaking at the convention, a snub that Manafort told NBC's "Today" show is "embarrassing the state" of Ohio.

Kasich adviser John Weaver shot back: "Governor Kasich has made it clear why he hasn't endorsed Mr. Trump. They share a different world view in how to move the country forward."

Some of the party's best diverse talent was missing from Cleveland or limiting their participation, including U.S. Senator Marco Rubio of Florida, a Cuban-American, and South Carolina Governor Nikki Haley, an Indian-American.

Many Republicans feel the party is in sore need of more Republicans like Rubio and Haley to appeal to a broader segment of the electorate.

As Republican National Committee Chairman Reince Priebus gaveled the convention to order, Rubio was in Fort Myers, Florida, talking about how to tackle toxic algae polluting some of the state's waterways.

Rubio, who lost to Trump in the primary battle and is running for re-election to the U.S. Senate, is to deliver a short videotaped message to the convention on Wednesday.

Haley is to speak at a breakfast for the South Carolina delegation in Cleveland on Wednesday.

"Chairman Reince Priebus asked if Governor Haley would speak at the convention a couple weeks ago. Governor Haley was grateful for the invitation and looks forward to attending the convention, but, as we have said before, she has no plans to speak so she declined the opportunity," said her deputy chief of staff, Rob Godfrey.

Romney, who has been a prominent voice among the anti-Trump forces, was in Wolfeboro, New Hampshire, with 36 members of his family for their annual summer gathering, a spokeswoman said.


Danny Diaz, who was campaign manager for Jeb Bush's presidential campaign, said the convention is missing a chance to show off some of its most talented Republican politicians.

"It speaks to where we are as a party at the moment more than anything else," he said.

Former Vice President Dick Cheney was in Wyoming helping the congressional campaign of his daughter, Liz Cheney, and former Secretary of State Condoleezza Rice, who was talked about as a possible vice presidential running mate for Trump, was at home in Palo Alto, California.

"Writing her book about democracy!" said her chief of staff, Georgia Godfrey.

Some of Trump's former rivals for the nomination are speaking in Cleveland, like U.S. Senator Ted Cruz of Texas, former Texas Governor Rick Perry, New Jersey Governor Chris Christie and former Arkansas Governor Mike Huckabee.

But some of the others felled by Trump were doing other things.

U.S. Senator Rand Paul of Kentucky, an eye doctor, was providing free eye care in Paducah, Kentucky. U.S. Senator Lindsey Graham was in his home state of South Carolina for the week.

Republican strategist Ryan Williams said the no-shows are evidence of a party still deeply fractured, despite the calls for unity.

"It shows that Trump has more work to do uniting the party and that he should continue to try to bring Republicans together even after the convention," Williams said.

(Additional reporting by Emily Stephenson and Ginger Gibson; Editing by Caren Bohan and Ross Colvin)